All you need to know about olive oil

May 9, 2012 BY: LISA

Olive Oil

While most plant based oils are good for you there is no doubt that due to its high daily use in the Mediterranean diet olive oil is the best researched oil. Below are some facts about why olive oil is good for you and how best to purchase and store it.

From the Better Health Channel:

Olive oil is a major component in the Mediterranean diet. Evidence shows that Mediterranean populations have reduced risk for certain chronic diseases and extended life expectancy compared with other populations in the world, despite their high dietary fat intake, which is usually in excess of 30 per cent of their total energy intake

A famous study carried out in the 1950s highlighted differences in diseases that occurred between Mediterranean populations and those living in northern Europe and North America, and compared their diets. Over 30 years, it was found that the Mediterranean diet was associated with low rates of conditions like cardiovascular disease (CVD) and certain types of cancers, as well as increased
life expectancy.

Studies have also shown that olive oil consumption may have a protective role on breast, colon, lung, ovarian and skin cancer development. Compounds specific olive oil, known as phenolics, seem to possess free radical-scavenging properties and so may be able to reduce oxidative damage to DNA.

Types of olive oil
Olive oil is produced by the pressing or crushing of olive fruit. It comes indifferent grades, depending on the amount of processing involved. There are unrefined (virgin) grades and refined grades. The less the oil is refined by heat and chemical treatments, the higher the quality of the oil.

Virgin varieties of olive oil are believed to offer the greatest health benefits as they retain most of the nutrients from the olive fruit.

Varieties include:

Extra virgin – This oil is considered to be the premium grade of olive oil. It is made from the first pressing of olives. The oil is extracted by the traditional cold-pressing method, where no chemicals and only a small amount of heat are applied.

Virgin – This oil is produced from the second pressing of olives or from the second-best grade of olives by cold-pressing, without use of chemicals and use of little heat.

Olive oil – Also marketed as ‘pure’ olive oil. This type of oil is non-virgin,commercial-grade olive oil. It is ‘pure’ olive oil to the extent that it consists only of olive oil. This grade of olive oil consists of the inferior oil that is a result of subsequent pressings after the virgin oil has been extracted from lower-quality olives. This oil then undergoes a refining process involving heat, chemical solvents, high pressure and filtration treatments. This oil is then mixed with a small quantity of
virgin olive oil to restore colour and flavour.

Light and extra light – These oils are produced from the last pressing of olives. They are more refined and of lower quality than the other grades. There is little of the natural olive flavour and colour in these oils

Storing Olive oil:

Source: http://recipes.howstuffworks.com/how-olive-oil-works3.htm

Heat, air and light are enemies to oil. These elements help create free radicals which eventually lead to excessive breakdown and rancidity of the oil.

Best storage is in tinted glass or stainless steel, avoid plastic as the oil can absorb some of the plastic compounds in the bottle.

Keep it cool around the same temperature as a wine cellar = 14 degrees Celsius.

The most practical place in the ordinary household is a dark cool cupboard away from the stove. Olive oil will store for up to one
year under these conditions. You can refrigerate olive oil however while it is cold it will go cloudy but this should clear again when back at room temperature and doesn’t affect the flavour of the oil.

Olive oil is at its peak 2-3months after pressing. The nutrient content degrades over time. A study has shown that even under
perfect storage conditions for 12 months:

Vitamin E is completely gone

40% of beta-carotene has decreased

Phenol level has decreased.

Both processing and storage of fruit and oil contribute to flavour and overall quality of olive oil. (Guitierrez& Fernandez 2003)

In most cases quality parameters change by the time the oil reaches the consumer.

The volatile compounds within the oil are responsible for the aroma and this varies with:

Fruit maturity- the flavours are produced when the fruit it ripening

Condition of the fruit at harvest

Differences in post harvest handling

Extraction methods

Temperature

Storage of both fruit and oil changes the flavours. The longer the storage the more likely to be off flavours.

(C.M Kalua et al. Food Chemistry 100(2007) 273-286)

Smoking Point:

The smoking point is the point where the oil starts to break down and begin to smoke. Depending on the source olive oil has variable smoking points, one article I read suggested that the purer and clearer the oil –that is extra virgin the higher the smoking point. So due to its price you probably wouldn’t deep fry in olive oil but you can fry with it and it’s obviously ideal for using straight up on a salad just like in the Mediterranean!

Bottom Line:

Potentially buying small bottles of good quality locally sourced extra virgin olive oil is the best way of guaranteeing that your olive oil is fresh and gives you longer lasting health benefits and flavour.

Enjoy!

Lisa Renn – Accredited Practisng Dietitian APD

Comments

[…] Here is the original post: All you need to know about olive oil :: Body Warfare Nutrition … […]

[…] All you need to know about olive oil :: Body Warfare Nutrition … Depending on the source olive oil has variable smoking points, one article I read suggested that the purer and clearer the oil –that is extra virgin the higher the smoking point. So due to its price you probably wouldn't deep fry in . Potentially buying small bottles of good quality locally sourced extra virgin olive oil is the best way of guaranteeing that your olive oil is fresh and gives you longer lasting health benefits and flavour. Enjoy! Lisa Renn – Accredited Practisng . […]

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